Subspecies and Distribution. U. c. cinereoargenteus Schreber, 1775 — E USA. U. c. borealis Merriam, 1903 — SE Canada and USA (New England). U. c. californicus Mearns, 1897 — SW USA (S California). U. c. costaricensis Goodwin, 1938 — Costa Rica. U. c. flornidanus Rhoads, 1895 — Gulf of Mexico. U. c. fraterculus Elliot, 1896 — Mexico (Yucatan). U. c. furvus G. M. Allen & Barbour, 1923 — Panama. U. c. guatemalae G. S. Miller, 1899 — S Mexico S to Nicaragua. U. c. madrensis Burt & Hooper, 1941 — Mexico (S Sonora, SW Chihuahua & NW Durango). U. c¢. nigrirostris Lichtenstein, 1830 — SW Mexico. U. c. ocythous Bangs, 1899 — USA (Central Plains) and adjoining S Canada. U. ¢. orinomus Goldman, 1938 — S Mexico (Isthmus of Tehuantepec). U. c. perunsularis Huey, 1928 — NW Mexico (Baja California). U. c. scottit Mearns, 1891 — N Mexico and SW USA. U. c. townsend: Merriam, 1899 — W USA (California & Oregon). U. c. venezuelae]. A. Allen, 1911 — Colombia, Venezuela. in Canidae - Don E. Wilson (Lynx Edicions, 2009)